DE102018133526A1 - OPTOELECTRONIC SEMICONDUCTOR COMPONENT WITH AN INTERLAYER AND METHOD FOR PRODUCING THE OPTOELECTRONIC SEMICONDUCTOR COMPONENT - Google Patents

Abstract

An optoelectronic semiconductor component (10) comprises a first semiconductor layer (110) of a first conductivity type, the first semiconductor layer (110) having the composition AlGaN. The optoelectronic semiconductor component (10) further comprises a second semiconductor layer (120) of a second conductivity type, an active zone (115) between the first semiconductor layer (110) and the second semiconductor layer (120), the active zone (115) having a quantum well structure ( 114), and an intermediate layer (125) between the first semiconductor layer (110) and the active zone (115). The intermediate layer (125) comprises a semiconductor material with the composition AlGaN, with x * 1.05 y y 1 1.

Description

BACKGROUND

A light emitting diode (LED) is a light emitting device based on semiconductor materials. For example, light emitting diodes based on the AlGaN material system are used to provide light sources in the deep ultraviolet (DUV) range. Efforts are generally being made to increase the efficiency of light-emitting diodes based on the AlGaN material system.

The object of the present invention is to provide an improved optoelectronic semiconductor component and an improved method for producing an optoelectronic semiconductor component.

According to embodiments, the object is achieved by the subject matter and the method of the appended claims. Advantageous further developments are defined in the dependent claims.

SUMMARY

An optoelectronic semiconductor component comprises a first semiconductor layer of a first conductivity type, the first semiconductor layer having the composition Al _x Ga _1-x N. The optoelectronic semiconductor component furthermore comprises a second semiconductor layer of a second conductivity type, an active zone between the first semiconductor layer and the second semiconductor layer, the active zone having a quantum well structure, and an intermediate layer between the first semiconductor layer and the active zone. The intermediate layer comprises a semiconductor material with the composition Al _y Ga _1-y N, with x * 1, 05≤ y ≤1.

For example, the intermediate layer has a layer thickness greater than 2 nm, greater than 8 nm or greater than 40 nm. The layer thickness of the intermediate layer can be less than 100 nm.

For example, the intermediate layer is undoped. According to further embodiments, the intermediate layer can be of the first conductivity type.

For example, the intermediate layer can have a layer stack with alternately stacked first partial layers and second partial layers. The first partial layers have the composition Al _{y '} Ga _1-y' N (0 ≤ y '≤1) with a layer thickness d'. The second partial layers have the composition Al _{y ''} Ga _{1-y ''} N (0 ≤y ”≤y`) and a layer thickness d". For example, the average Al content of the intermediate layer 125 in this case defined as follows:
y _avg = (y '* d' + y '' * d '') / (d '+ d''), whereby the following also applies: x * 1.05 ≤ y _avg ≤1.

The layer thicknesses of the first and second partial layers can each be greater than 1 nm and less than 10 nm. For example, the first and second sublayers can form a superlattice. The maximum layer thickness of the superlattice can be less than 100 nm.

According to embodiments, the first semiconductor layer has the composition Al _x Ga _1-x N with 0.3 x x 0 0.95.

The intermediate layer can directly adjoin the active zone.

According to embodiments, an aluminum content of the intermediate layer can increase or decrease with increasing distance from the active zone.

A method for producing an optoelectronic semiconductor component comprises forming a first semiconductor layer of a first conductivity type, the first semiconductor layer having the composition Al _x Ga _1-x N. The method further includes forming a second semiconductor layer of a second conductivity type, forming an active zone between the first semiconductor layer and the second semiconductor layer, the active zone having a quantum well structure, and forming an intermediate layer between the first semiconductor layer and the active zone. The intermediate layer comprises a semiconductor material with the composition Al _y Ga _1-y N, with x * 1, 05≤ y ≤1.

For example, the first semiconductor layer can be formed from a metal-supersaturated gas mixture.

According to embodiments, the intermediate layer can be formed from a metal-supersaturated gas mixture. A degree of metal supersaturation may be lower for the intermediate layer than for the first semiconductor layer. For example, the degree of metal supersaturation for the growth of the intermediate layer can be at least 10% smaller than for the growth of the first semiconductor layer.

The optoelectronic semiconductor component has an optoelectronic device as described above. The optoelectronic device can be selected from a UV disinfection device, a UV curing device or a UV measuring device.

Figure list

• 1 zeigt eine Querschnittsansicht eines optoelektronischen Halbleiterbauelements gemäß Ausführungsformen.
• 2A zeigt Details einer Zwischenschicht gemäß Ausführungsformen.
• 2B zeigt die ausgestrahlte Lichtleistung in Abhängigkeit von einer Schichtdicke der Zwischenschicht.
• 3A zeigt ein Messergebnis einer Messung mit dem Transmissionselektronenmikroskop.
• 3B zeigt ein weiteres Ergebnis einer Messung mit dem Transmissionselektronenmikroskop.
• 4A zeigt eine Querschnittsansicht eines optoelektronischen Halbleiterbauelements gemäß weiteren Ausführungsformen.
• 4B zeigt eine Messung der internen Quanteneffizienz bei einer Temperatur von 12 K.
• 4C zeigt eine Messung der internen Quanteneffizienz bei einer Messung bei Raumtemperatur.
• 5A zeigt eine Querschnittsansicht eines optoelektronischen Halbleiterbauelements gemäß weiteren Ausführungsformen.
• 5B und 5C zeigen jeweils Ergebnisse der Messung der Photolumineszenz.
• 6 fasst ein Verfahren gemäß Ausführungsformen zusammen.
• 7 zeigt eine optoelektronische Vorrichtung gemäß Ausführungsformen.

The accompanying drawings serve to understand exemplary embodiments of the invention. The drawings illustrate exemplary embodiments and, together with the description, serve to explain them. Further exemplary embodiments and numerous of the intended advantages result directly from the detailed description below. The elements and structures shown in the drawings are not necessarily drawn to scale with respect to one another. The same reference numerals refer to the same or corresponding elements and structures.

• 1 shows a cross-sectional view of an optoelectronic semiconductor component according to embodiments.
• 2A shows details of an intermediate layer according to embodiments.
• 2 B shows the emitted light output as a function of a layer thickness of the intermediate layer.
• 3A shows a measurement result of a measurement with the transmission electron microscope.
• 3B shows another result of a measurement with the transmission electron microscope.
• 4A shows a cross-sectional view of an optoelectronic semiconductor component according to further embodiments.
• 4B shows a measurement of the internal quantum efficiency at a temperature of 12 K.
• 4C shows a measurement of the internal quantum efficiency when measured at room temperature.
• 5A shows a cross-sectional view of an optoelectronic semiconductor component according to further embodiments.
• 5B and 5C each show results of the measurement of the photoluminescence.
• 6 summarizes a method according to embodiments.
• 7 shows an optoelectronic device according to embodiments.

DETAILED DESCRIPTION

In the following detailed description, reference is made to the accompanying drawings, which form a part of the disclosure and in which specific exemplary embodiments are shown for purposes of illustration. In this context, a directional terminology such as “top”, “bottom”, “front”, “back”, “over”, “on”, “in front”, “behind”, “front”, “back” etc. is applied to the Alignment of the figures just described related. Since the components of the exemplary embodiments can be positioned in different orientations, the directional terminology is only used for explanation and is in no way restrictive.

The description of the exemplary embodiments is not restrictive, since other exemplary embodiments also exist and structural or logical changes can be made without deviating from the scope defined by the patent claims. In particular, elements of exemplary embodiments described below can be combined with elements of other exemplary embodiments described, unless the context provides otherwise.

The terms “wafer” or “semiconductor substrate” used in the following description may include any semiconductor-based structure that has a semiconductor surface. Wafers and structures are to be understood to include doped and undoped semiconductors, epitaxial semiconductor layers, optionally supported by a base pad, and other semiconductor structures. For example, a layer made of a first semiconductor material can be grown on a growth substrate made of a second semiconductor material or of an insulating material, for example on a sapphire substrate. Other examples of materials for growth substrates include glass, silicon dioxide, quartz, silicon, SiC, AlN, GaN or a ceramic.

Depending on the intended use, the semiconductor material described in the context of the present description can be based on a direct or an indirect semiconductor material. Examples of semiconductor materials which are particularly suitable for generating electromagnetic radiation include, in particular, nitride semiconductor compounds, by means of which, for example, ultraviolet, blue or longer-wave light can be generated, such as, for example, GaN, InGaN, AlN, AlGaN, AlGaInN, AlGaInBN, phosphide semiconductor compounds, by means of which, for example, green or longer-wave light can be generated, such as GaAsP, AlGaInP, GaP, AlGaP, as well as other semiconductor materials such as GaAs, AlGaAs, InGaAs, AlInGaAs, SiC, ZnSe, ZnO, Ga ₂ O ₃ , diamond, hexagonal BN and combinations of the materials mentioned. The stoichiometric ratio of the compound semiconductor materials can vary. Further examples of semiconductor materials can include silicon, silicon germanium and germanium.

The term “substrate” generally encompasses insulating, conductive or semiconductor substrates.

The terms “lateral” and “horizontal”, as used in this description, are intended to describe an orientation or alignment that runs essentially parallel to a first surface of a substrate or semiconductor body. This can be the surface of a wafer or a chip (die), for example.

The horizontal direction can lie, for example, in a plane perpendicular to a growth direction when layers are grown.

The term “vertical” as used in this description is intended to describe an orientation that is essentially perpendicular to the first surface of a substrate or semiconductor body. The vertical direction can correspond, for example, to a growth direction when layers are grown.

Insofar as the terms “have”, “contain”, “comprise”, “exhibit” and the like are used here, they are open terms that indicate the presence of the said elements or features, but the presence of further elements or features do not exclude. The indefinite articles and the definite articles include both the plural and the singular, unless the context clearly indicates otherwise.

In the context of this description, the term “electrically connected” means a low-resistance electrical connection between the connected elements. The electrically connected elements do not necessarily have to be connected directly to one another. Further elements can be arranged between electrically connected elements.

The term “electrically connected” also includes tunnel contacts between the connected elements.

Examples of optoelectronic semiconductor devices are described below. In particular, LEDs are described. However, the concepts can also be applied to other optoelectronic semiconductor components and are therefore not restricted to light-emitting diodes. Other specific examples include, among others, semiconductor laser devices, such as surface emitting semiconductor laser devices, photodetectors, sensors, and others.

1 shows a schematic cross-sectional view of an optoelectronic semiconductor component according to embodiments. The optoelectronic semiconductor component 10 comprises a first semiconductor layer 110 of a first conductivity type, a second semiconductor layer 120 of a second conductivity type as well as an active zone 115 between the first semiconductor layer 110 and the second semiconductor layer 120 . The first semiconductor layer 110 has the composition Al _x Ga _{1 x} N. The active zone has a quantum well structure. The optoelectronic semiconductor component 10 also includes an intermediate layer 125 between the first semiconductor layer 110 and the active zone 115 . The intermediate layer 125 comprises a semiconductor material with the composition Al _y Ga _1-y N. The following applies: x · 1.05 y y 1. 1. For example, the intermediate layer 125 be n-doped with Si.

The active zone 115 has a quantum well structure for generating radiation 114 , for example a single quantum well structure (SQW, single quantum well) or a multiple quantum well structure (MQW, multi quantum well). The term “quantum well structure” has no meaning with regard to the dimensionality of the quantization. It includes quantum wells, quantum wires and quantum dots as well as any combination of these layers.

The active zone 115 can, for example, have partial layers with different electrical band gaps, the corresponding partial layers being stacked one on top of the other. For example, a material can have a smaller band gap (quantum well layer 113 ) between two barrier layers 116 be arranged with a larger band gap. If the layer thickness of the partial layer with the smaller band gap lies in the range of the de Broglie wavelength of electrons, the energy states within the partial layer with the smaller band gap are quantized and a quantum well structure is formed. Depending on the number of sub-layers with a smaller band gap in which quantized energy levels form, one speaks of an active zone with a single quantum well structure or of an active zone with a multiple (MQW) quantum well structure.

One or more electron blocking layers 117 For example, which can contain AlGaN and can be p-doped, are above the active zone 115 educated. A second semiconductor layer 120 is over the electron blocking layer 117 arranged. For example, the second semiconductor layer 120 a Mg p-doped AlGaN layer. A contact layer 123 can over the second semiconductor layer 120 be arranged. For example, the contact layer 123 Mg p-doped GaN. A second contact element 135 can over the contact layer 123 be arranged. The layers and layer thicknesses listed here are given as examples, and other layer thicknesses or dopants can be used. Furthermore, layers can be omitted or added be as long as it works the optoelectronic semiconductor device 10 not affected.

For example, the first semiconductor layer 110 be of an n-conductivity type, and the second semiconductor layer 120 is of a p-conductivity type. For example, the first semiconductor layer 110 the composition Al _x Ga _1-x N with 0.3 <x ≤ 0.95. The first semiconductor layer 110 can, for example, have a layer thickness of 0.5 to 3 μm, for example approximately 1.5 μm. The first semiconductor layer 110 can, for example, over a transparent substrate 100 be arranged. For example, the substrate 100 be a sapphire substrate. Additional layers can be arranged within the semiconductor layer structure.

For example, one or more buffer layers 105 between the substrate 100 and the first semiconductor layer 110 be arranged. The buffer layers 105 can have, for example, several Al _x Ga _y In _1-xy N layers with different compositions or composition ratios. These buffer layers can be used to reduce the density of spiral or helical dislocations, for example. This also allows tension to be set. A layer thickness of the buffer layer (s) 105 can be up to 10 µm, for example. The buffer layer 105 can also be omitted. For example, it can be omitted if a native substrate such as AlN is used as the substrate 100 is used.

The first semiconductor layer 110 can, for example, via a first contact element 130 be connected electrically. The second semiconductor layer 120 can, for example, via a second contact element 135 be connected electrically. By applying a suitable voltage between the first contact element 130 and the second contact element 135 can, for example, within the active zone 115 electromagnetic radiation 20 be emitted.

In the active zone 115 generated electromagnetic radiation 20 can, for example, over a main surface 101 as well as over side surfaces 102 of the substrate 100 be issued. Generated electromagnetic radiation 20 can possibly also over the surface of the layer 135 be issued.

The intermediate layer 125 has on average a higher aluminum content than the first semiconductor layer 110 on. For example, the aluminum content of the intermediate layer 125 at least 5% or possibly at least 10% higher than the aluminum content of the first semiconductor layer 110 . For example, the intermediate layer can have a layer thickness greater than 2 nm or greater than 8 nm or even greater than 20 nm. According to further embodiments, the layer thickness of the intermediate layer can 125 be smaller than 100 nm. With larger layer thicknesses, the electron injection can be impaired. It was found that by inserting the intermediate layer 125 between the first semiconductor layer 110 and the active zone 115 the radiated power of the electromagnetic radiation can be greatly increased.

According to embodiments, the intermediate layer 125 be undoped or be doped, for example at a doping level up to 5E19 cm ^-3 . Furthermore, the Al content in the intermediate layer 125 vary. For example, the Al content can increase towards the active zone.

2A shows a cross-sectional view of the intermediate layer 125 according to further embodiments. According to further embodiments, the intermediate layer can 125 a large number of first and second sub-layers 126 , 127 have the composition AlGaN, each with a different Al content. For example, the first sub-layers have 126 the composition Al _{y '} Ga _1-y' N (0 ≤ y '≤1) with a layer thickness d', and the second partial layers 127 have the composition Al _{y ''} Ga _{1-y ''} N (0 ≤y "≤y`) with a layer thickness d". For example, the average Al content of the intermediate layer 125 in this case defined as follows:
y <sub>avg</sub> = (y '* d' + y`` * d``) / (d` + d``), whereby the following also applies: x * 1.05 ≤ y _avg ≤1. The first and second sub-layers 126 , 127 are alternately stacked on top of each other.

For example, the individual layer thicknesses of the first and second partial layers 126 , 127 each be greater than 1 nm and less than 10 nm. The intermediate layer 125 with a large number of first and second sub-layers 126 , 127 forms a superlattice, for example. A total thickness of the intermediate layer 125 , which is designed as a superlattice, can be less than 100 nm.

2 B shows a measurement of the output radiation power as a function of the thickness (in nm) of the intermediate layer 125 each under the same operating conditions. As can be seen, the emitted radiation power increases with an increase in the layer thickness of the intermediate layer 125 on.

In general, according to embodiments, the optoelectronic semiconductor components described here emit electromagnetic radiation in a range from 210 to 360 nm. However, depending on the semiconductor layer system used, electromagnetic radiation can also be emitted in other wavelength ranges.

The 3A shows measurement results of a transmission electron microscopy measurement of the in 2A illustrated optoelectronic semiconductor component with a quantum well structure 114 which has five quantum wells. The quantum wells are each realized by a different aluminum content in the associated semiconductor layers. The intermediate layer 125 has a layer thickness of 4 nm. The solid line shows the aluminum content intended by setting the deposition parameters depending on a z-coordinate (see 1 ) and thus the intended course of the band structure. The dashed line shows the actually measured aluminum content as a function of the z coordinate and thus the course of the band structure in accordance with the quantum wells. As can be seen, the first quantum well, ie the quantum well on the left side of the horizontal axis, does not exist. The second and third quantum wells measured have a significantly lower aluminum content than intended.

3B shows a similar measurement for an optoelectronic semiconductor device with a layer thickness of the intermediate layer of 40 nm. As in 3B It can be seen that the measured position (dashed line) of the quantum wells roughly corresponds to the position (solid line) of the quantum wells, as is provided by setting the deposition parameters. Furthermore, these quantum wells are each designed with an approximately similar profile as intended.

As can be seen, the formation of the intermediate layer 125 before forming the quantum well structure 114 improves the quality of the quantum well structure. The quantum well structure 114 has several identical quantum wells with an Al content that corresponds to the intended Al content. With a larger layer thickness of the intermediate layer 115 an improved quality of the active zone is achieved.

4A shows a cross-sectional view of an optoelectronic semiconductor component 10 according to further embodiments. The optoelectronic semiconductor component 10 comprises a layer structure similar to that in 2A shown semiconductor device. The active zone 115 a plurality (e.g. 5) of barrier layers 116 and quantum well layers 113 . The quantum well layers each have a composition and layer thickness which are dimensioned such that quantized energy states in the quantum well layer 113 are present, which is arranged between two barrier layers. A top layer 122 , for example made of AlGaN, is over the top quantum well layer 113 educated. For example, the top layer 122 have the same composition as a barrier layer. For example, the top layer 122 have a greater layer thickness than usual barrier layers in order to avoid surface effects.

The 4B and 4C each show measurement results of quantum efficiency at 12 K on the one hand ( 4B) as well as room temperature ( 4C ) on the semiconductor layer structure, which is part of the optoelectronic semiconductor component 10 from 4A forms. For example, the measurement can be carried out on a layer structure that corresponds to the optoelectronic semiconductor component 10 without first and second contact element 130 , 135 corresponds. The quantum efficiency as a function of the irradiated laser power is shown. The measurements are in each case for different layer thicknesses of the intermediate layer 125 added. As can be seen, an efficiency occurs at a temperature of 12 K due to the freezing out of the defects and a negligible surface recombination, which depends on the layer thickness of the intermediate layer 125 is independent in each case. As in 4C is shown, the quantum efficiency rises sharply depending on the thickness of the intermediate layer at room temperature. If the thickness of the intermediate layer increases from 4 nm to 13 nm, the quantum efficiency can be increased by approximately 30%.

Like comparing the 4B and 4C shows can by the presence of the intermediate layer 125 Crystal defects can be reduced. As a result, the crystal quality of the quantum well structure 114 be improved.

5A shows a cross-sectional view of an optoelectronic semiconductor component according to further embodiments. Notwithstanding the in 4A The structure shown here is the active zone 115 formed as a single quantum well structure. In other words, is a quantum well layer 113 for the formation of the quantum well structure 114 between the barrier layer 116 and the top layer 122 arranged. For example, the top layer 122 have a similar composition to a barrier layer. The intermediate layer 125 is adjacent to the barrier layer 116 arranged.

The 5B and 5C each show photoluminescence measurements on optoelectronic semiconductor components 10 . The measurement of 5C performed on an optoelectronic semiconductor component, for example in 5A is shown, with a single quantum well structure. The measurement of 5B was on an optoelectronic semiconductor device 10 without intermediate layer 125 carried out. The optoelectronic semiconductor components 10 come from different positions of a processed wafer 104 .

The upper spectrum of the 5B shows a measurement on optoelectronic semiconductor components 10 which is a position opposite the "anti-flat" of the wafer 104 are removed. The lower spectrum of the 5B is the middle of the wafer 104 taken. Without an intermediate layer, only one emission takes place in the upper spectrum ( 1 ) instead of. This emission is due to emission in the bulk AlGaN layer. The lower spectrum of 5B shows an emission in place ( 1 ) instead, which is due to emission in the bulk AlGaN layer. In addition, emission takes place ( 2nd ) instead of. The emission in place ( 2nd ) is due to emission from the single quantum well structure. The emission wavelength is shorter than would be expected based on the deposition parameters. This means that there is not enough gallium in the single quantum well structure.

Again shows the upper spectrum of 5C a measurement on optoelectronic semiconductor components 10 which is a position opposite the "anti-flat" of the wafer 104 are removed. Here an emission takes the place ( 1 ) due to emission in the bulk AlGaN layer. In addition, emission takes the place ( 2nd ) due to emission from the single quantum well structure. The wavelength is larger than the emission wavelength in place ( 2nd ) of the lower spectrum of 5B , which shows that more gallium is built into the quantum well structure. The lower spectrum of 5C a significantly longer emission wavelength of emission ( 2nd ), which is in the range of the emission wavelength of a multiple quantum well structure. This shows that the single quantum well structure is more homogeneous.

Overall, therefore, due to the intermediate layer 125 the quantum wells in a more homogeneous manner, ie based on a wafer 104 , be formed. The incorporation of gallium into the quantum well structure is improved, which enables emission at a longer wavelength.

6 summarizes a method according to embodiments. A method for producing an optoelectronic semiconductor component comprises the formation ( S100 ) a first semiconductor layer 110 of a first conductivity type, the first semiconductor layer 110 has the composition Al _x Ga _1-x N. The process also includes training ( S130 ) a second semiconductor layer 120 of a second conductivity type as well as the training ( S120 ) an active zone 115 between the first semiconductor layer 110 and the second semiconductor layer 120 , the active zone 115 a quantum well structure 114 having. The process also includes training ( S110 ) an intermediate layer 125 between the first semiconductor layer 110 and the active zone 115 , with the intermediate layer 125 comprises a semiconductor material of the composition Al _y Ga _1-y N, with x · 1.05 y y 1 1.

The semiconductor layers can be formed, for example, by a MOVPE process (metal organic vapor phase epitaxy, “metal organic vapor phase epitaxy”), other suitable epitaxy processes or a MOCVD process (metal organic deposition from the gas phase, “metal organic chemical vapor deposition”). In order to grow a highly conductive n-AlGaN layer with an aluminum content between 30 and 95%, a high metal supersaturation is usually required during the deposition in order to reduce the compensation of the metal vacancy complexes.

In general, the aluminum supersaturation σ is defined as (P / P ₀ ) -1, where P denotes the partial pressure of aluminum components and P ₀ the vapor pressure of aluminum components at thermodynamic equilibrium. Gallium supersaturation is defined in a similar way. When an AlGaN layer grows, a metal supersaturation is defined as the sum of the aluminum and gallium supersaturations.

With high metal supersaturation, spiral or helical growth of the respective layers is promoted, which ultimately leads to a rough surface.

In that the intermediate layer 125 after the formation of the first semiconductor layer and before the formation of the active zone, on the one hand the surface roughness can be reduced. This is achieved by using the intermediate layer 125 Dislocations caused by spiral or helical growth are leveled out. As a result, a well-defined and therefore sharp transition between the intermediate layer can occur 125 and the active zone 115 can be achieved. This improves the profile of the active zone, in particular the profile of the quantum well structure. Furthermore, the homogeneity of the quantum well structure is improved. As a result, better overall quantum efficiency and charge injection efficiency are achieved.

For example, the intermediate layer is grown at a lower metal supersaturation than the metal supersaturation that is present when the first semiconductor layer is formed. A lower metal supersaturation can be set, for example, by reducing the growth rate, the ratio of the components of the fifth group compared to the components of the third group is varied or by increasing the temperature during growth. For example, the ratio of the components of the fifth group can be varied depending on the growth atmosphere. For example, the metal supersaturation for growth of the intermediate layer should 125 at least 10% less than for the first semiconductor layer 110 be. Lower metal supersaturation leads to a higher concentration of metal vacancies. These contain more Ga vacancies because the Al-N bond is stronger than the Ga-N bond. Therefore, a higher aluminum content is required to reduce the Ga vacancies and the Ga vacancy complexes.

According to further embodiments, the intermediate layer can 125 can also be implemented as a superlattice structure and a multiplicity of first and second partial layers 126 , 127 included, as with reference to 2A has been described. Here you can deposit the sub-layers 126 , 127 an average supersaturation can be set which is less than that for the deposition of the first semiconductor layer 110 . The supersaturation must occur when the partial layer is deposited 126 or 127 not necessarily be less than the supersaturation when the first semiconductor layer is deposited 110 .

According to further embodiments, an aluminum content of the intermediate layer can 125 vary. For example, the aluminum content can increase from the first semiconductor layer to the active zone. Furthermore, the intermediate layer 125 or the interlayer stack, which has a plurality of first and second partial layers 126 , 127 has to be endowed. For example, the intermediate layer can be used at the same time 125 be doped, for example at a concentration less than 5E19 cm ^-3 , and the aluminum content can increase with increasing distance from the active zone. As a result, the electron concentration can be increased via polarization doping, which further improves the charge carrier injection.

The experimental results confirm that by forming the intermediate layer between the first semiconductor layer and the active zone 115 the light output power can be increased. The internal quantum efficiency can be increased by increasing the thickness of the intermediate layer 125 increase. Furthermore, the non-radiative charge carrier recombination within the quantum well structure is reduced. Overall, the presence of the intermediate layer leads 125 to a better quality of the quantum well structure 114 . In addition, due to the greater homogeneity of the quantum well structure 114 the charge injection efficiency can be increased. As a result, an improved external quantum efficiency is achieved overall.

7 shows an optoelectronic device according to embodiments. The optoelectronic device 15 comprises the optoelectronic semiconductor component described here 10 . For example, the optoelectronic device 15 a device for disinfection using UV radiation. For example, the optoelectronic device 15 can be used to disinfect water or air. In addition, the optoelectronic device 15 can be used as a UV measuring device or as a curing device for polymers.

Although specific embodiments have been illustrated and described herein, those skilled in the art will recognize that the specific embodiments shown and described may be replaced by a variety of alternative and / or equivalent configurations without departing from the scope of the invention. The application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, the invention is limited only by the claims and their equivalents.

Reference list

10th

optoelectronic semiconductor component

15

optoelectronic device

20

electromagnetic radiation

100

Substrate

101

Main surface of the substrate

102

Side surface of the substrate

104

Wafer

105

AlN layer

110

first semiconductor layer

113

Quantum well layer

114

Quantum well structure

115

active zone

116

Barrier layer

117

Electron blocking layer

120

second semiconductor layer

122

Top layer

123

Contact layer

125

Intermediate layer

126

first sub-layer

127

second sub-layer

130

first contact element

135

second contact element

Claims (19)

An optoelectronic semiconductor device (10) comprising: a first semiconductor layer (110) of a first conductivity type, the first semiconductor layer (110) having the composition Al _x Ga _1-x N; a second semiconductor layer (120) of a second conductivity type; an active zone (115) between the first semiconductor layer (110) and the second semiconductor layer (120), the active zone (115) having a quantum well structure (114), and an intermediate layer (125) between the first semiconductor layer (110) and the active zone (115), the intermediate layer (125) comprising a semiconductor material of the composition Al _y Ga _1-y N, with x * 1, 05≤ y ≤1. Optoelectronic semiconductor component (10) Claim 1 , in which the intermediate layer (125) has a layer thickness greater than 2 nm. Optoelectronic semiconductor component (10) Claim 1 or 2nd , in which the intermediate layer (125) has a layer thickness greater than 8 nm. Optoelectronic semiconductor component (10) Claim 3 , in which the intermediate layer (125) has a layer thickness greater than 40 nm. Optoelectronic semiconductor component (10) according to one of the preceding claims, in which the intermediate layer (125) has a layer thickness of less than 100 nm. Optoelectronic semiconductor component (10) according to one of the preceding claims, in which the intermediate layer (125) is undoped. Optoelectronic semiconductor component (10) according to one of the Claims 1 to 4th , in which the intermediate layer (125) is of the first conductivity type. Optoelectronic semiconductor component (10) according to one of the preceding claims, in which the intermediate layer (125) comprises a layer stack with alternately stacked first partial layers (126) of the composition Al _{y '} Ga _1-y' N (0 ≤ y '≤1) with a Layer thickness d ', and second sub-layers (127) of the composition Al _y'' Ga _1-y'' N (0 ≤y``≤y') with a layer thickness d ", where x * 1.05≤ y _avg ≤ 1 and y _avg = (y '* d' + y '' * d '') / (d '+ d''). Optoelectronic semiconductor component (10) Claim 8 , in which the layer thicknesses of the first and second partial layers (126, 127) are each greater than 1 nm and less than 10 nm. Optoelectronic semiconductor component (10) Claim 8 or 9 , in which the layer thickness of the intermediate layer is less than 100 nm. Optoelectronic semiconductor component according to one of the preceding claims, in which the first semiconductor layer (110) has the composition Al _x Ga _1-x N with 0.3 ≤ x ≤ 0.95. Optoelectronic semiconductor component according to one of the preceding claims, in which the intermediate layer (125) directly adjoins the active zone (115). Optoelectronic semiconductor component according to one of the preceding claims, in which an aluminum content of the intermediate layer (125) decreases with increasing distance from the active zone. A method of manufacturing an optoelectronic semiconductor device (10) comprising: forming (S100) a first semiconductor layer (110) of a first conductivity type, the first semiconductor layer (110) having the composition Al _x Ga _1-x N; Forming (S130) a second semiconductor layer (120) of a second conductivity type; Forming (S120) an active zone (115) between the first semiconductor layer (110) and the second semiconductor layer (120), the active zone (115) having a quantum well structure (114), and forming (S110) an intermediate layer (125) between the first semiconductor layer (110) and the active zone (115), the intermediate layer (125) comprising a semiconductor material with the composition Al _y Ga _1-y N, with x * 1, 05≤ y ≤1. Procedure according to Claim 14 , in which the formation of the first semiconductor layer (110) from a metal supersaturated gas mixture. Procedure according to Claim 15 , in which the intermediate layer (125) is formed from a metal supersaturated gas mixture and a degree of metal supersaturation for the deposition of the intermediate layer (125) is lower than for the first semiconductor layer (110). Procedure according to Claim 16 , in which a degree of metal supersaturation for the deposition of the intermediate layer (125) is at least 10% less than for the first semiconductor layer (110). Optoelectronic device (15), which the optoelectronic semiconductor component (10) according to one of the Claims 1 to 13 having. Optoelectronic device (15) after Claim 18 that is selected from a UV Disinfection device, a UV curing device or a UV measuring device.

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